@misc{die+festigkeits+eigenschaften+von+eisen+und+stahl,
    author = {Styffe, Knut i Sandberg, Christer Petter},
    title = {Die Festigkeits-Eigenschaften von Eisen und Stahl},
    address = {Weimar},
    publisher = {Bernhard Friedrich Voigt},
    date = {1870}
}